1. Field of the Invention
The present invention relates to a method for repairing the refractory lining wall of a furnace, and more particularly to a method and apparatus for repairing the refractory lining wall of a blast furnace.
2. Description of the Prior Art
As is well known in the iron and steel industry, the wall of a blast furnace is composed of refractory bricks which line the inside of the steel shell of the blast furnace. The refractory bricks of this wall suffer considerable wear from contact with the furnace charge and the molten pig iron in the furnace.
Various methods and means for repairing the above-mentioned worn refractory bricks have heretofore been proposed. The repair of the refractory lining walls of blast furnaces has been carried out by injecting a repair material in a hot or cold state into the spot to be repaired in the furnace. The repair material can be divided into the following types: heat setting, hydraulic setting, and chemical setting. When the repair material is to be introduced under pressure in a hot state, a heat setting material is generally used, and when the material is to be introduced in a cold state, either a hydraulic setting or a chemical setting material is used. It is particularly important that the refractory composition of the repair material have excellent fluidity so as not to clog in an injector or hose. Ordinarily a refractory composition of either the clay or alumina type is used.
The conventional prior art methods for repairing the refractory lining wall of a furnace can be listed as follows:
(1) Placing an injection pipe on the outer shell of the furnace and injecting a repair material under pressure therethrough (FIG. 1).
(2) Inserting an injection nozzle for the repair material through the desired part of the furnace wall and extending into the furnace and injecting a repair material under pressure which is ejected from the nozzle within the furnace in directions perpendicular to the injection nozzle (FIG. 2).
The methods (1) and (2) have the common disadvantage that, since no reinforcing studs are provided, the repaired portion of the refractory lining is apt to peel or fall out so that the repaired refractory lining has only a short service life.